The effects of non-interval PUVA treatment on Langerhans cells and contact hypersensitivity

Although application of topical psoralen followed immediately by ultraviolet-A irradiation (non-interval PUVA) was reported to be effective in the treatment of psoriasis, its precise mechanisms of action have not yet been explored. Since regular topical PUVA therapy, consisting of the topical application of psoralen followed by UVA exposure 1-2 h later, can change the number and morphology of Langerhans cells (LCs) and inhibit contact hypersensitivity (CHS), we investigated whether these same effects may be induced by non-interval PUVA. Our results showed that no differences exist between these two types of PUVA treatment. Non-interval PUVA treatments of 3 J/cm2 produced no erythematous reactions and resulted in changes in the number and morphology of LCs. The non-interval regimen also inhibited CHS to dinitrofluorobenzene applied to the treated skin by inducing the suppressor lymphocytes. These results suggest that there might be a link between the observed changes of the LCs and the effectiveness of non-interval PUVA therapy in the treatment of psoriasis, through a mechanism other than the inhibition of DNA synthesis of psoriatic keratinocytes.

[Effect of sodium 18 beta-glycyrrhetate on experimental arrhythmia]

The effect of sodium 18 beta-glycyrrhetate (SGA) on experimental arrhythmia was investigated. The result shows that SGA strongly counteracts arrhythmia induced by chloroform of chloroform adrenaline, lengthens the appearance time of arrhythmia induced by CaCl2, slightly retards the heart rate of rats and rabbits, and partly antagonizes the acceleration effect of isoproterenol on rabbit hearts.

The catalytic consequences of experimental evolution. Studies on the subunit structure of the second (ebg) beta-galactosidase of Escherichia coli, and on catalysis by ebgab, an experimental evolvant containing two amino acid substitutions

1. The ratio of ebgA-gene product of ebgC-gene product in the functional aggregate of ebg beta-galactosidases was determined to be 1:1 by isolation of the enzyme from bacteria grown on uniformly radiolabelled amino acids and separation of the subunits by gel-permeation chromatography under denaturing conditions. 2. This datum, taken together with a recalculation of the previous ultracentrifuge data [Hall (1976) J. Mol. Biol. 107, 71-84], analytical gel-permeation chromatography and electron microscopy, strongly suggests an alpha 4 beta 4 quaternary structure for the enzyme. 3. The second chemical step in the enzyme turnover sequence, hydrolysis of the galactosyl-enzyme intermediate, is markedly slower for ebgab, having both Asp-97----Asn and Trp-977----Cys changes in the large subunit, than for ebga (having only the first change) and ebgb (having only the second), and is so slow as to be rate-determining even for an S-glycoside, beta-D-galactopyranosyl thiopicrate, as is shown by nucleophilic competition with methanol. 4. The selectivity of galactosyl-ebgab between water and methanol on a molar basis is 57, similar to the value for galactosyl-ebgb. 5. The equilibrium constant for the hydrolysis of lactose at 37 degrees C is 152 +/- 19 M, that for hydrolysis of allolactose is approx. 44 M and that for hydrolysis of lactulose is approx. 40 M. 6. A comparison of the free-energy profiles for the hydrolyses of lactose catalysed by the double mutant with those for the wild-type and the single mutants reveals that free-energy changes from the two mutations are not in general independently additive, but that the changes generally are in the direction predicted by the theory of Burbaum, Raines, Albery & Knowles [(1989) Biochemistry 28, 9283-9305] for an enzyme catalysing a thermodynamically irreversible reaction. 7. Michaelis-Menten parameters for the hydrolysis of six beta-D-galactopyranosylpyridinium ions and ten aryl beta-galactosides by ebgab were measured. 8. The derived beta 1g values are the same as those for ebgb (which has only the Trp-977----Cys change) and significantly different from those for ebgo (the wild-type enzyme) and ebga. 9. The alpha- and beta-deuterium secondary isotope effects on the hydrolysis of the galactosyl-enzyme of 1.08 and 1.00 are difficult to reconcile with the pyranose ring in this intermediate being in the 4C1 conformation.

Dinucleotide repeat polymorphism at the D11S436 locus

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Localization of the highly polymorphic microsatellite DXS456 on the genetic linkage map of the human X chromosome

The CA repeat microsatellite DXS456, with a heterozygosity of 77%, has been localized by multipoint linkage analysis in relation to 20 other genetic markers. DXS456 mapped to a 4.2-cM interval defined by the flanking markers DXS178 and DXS287. The maximum likelihood order of markers, cen-(DXYS1X/DXYS13X/DXYS2X/DXYS12X)-DXS366 -DXS178-DXS456-DXS287-DXS358-DXS267- qter, is favored by odds greater than 1000:1 over the subset of most likely alternative orders. Linkage of DXS456 can be inferred for at least six disease genes that are known to be linked to markers in the region Xq21.31-Xq25 and the marker will serve as an important index point for orienting these and other disease and marker loci in the region.

Studies on monoclonal antibody against recombinant human granulocyte colony-stimulating factor

Three hybridoma cell lines producing monoclonal antibodies (McAb) against recombinant human granulocyte colony-stimulating factor (rhG-CSF) have been established by fusing mouse myeloma cell line SP2/0 cells with spleen cells from a BALB/c mouse immunized with rhG-CSF. Ascites was obtained from BALB/c mice by injecting the hybridoma cells intraperitoneally. Three McAbs were purified by the caprylic acid-ammonium sulfate method. For each, the IgG subclass, valence and activity, molecular weight, specificity and affinity were determined. The applications of McAbs against rhG-CSF in the clinic and laboratory are discussed.

Metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) by cytochrome P450IIB1 in a reconstituted system

Several previous studies have suggested that cytochrome P450IIB1 is involved in the bioactivation of the tobacco-specific carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), in rats as well as in mouse lung microsomes. The present investigation was undertaken to study the metabolism of NNK by purified cytochrome P450IIB1 in a reconstituted system. The metabolites 4-hydroxy-4-(3-pyridyl) butyric acid (hydroxy acid), 4-oxo-4-(3-pyridyl) butyric acid (keto acid), 4-oxo-4-(3-pyridyl) butanol (keto aldehyde), 4-(methylnitrosamino)-1-(3-pyridyl-N-oxide)-1-butanone (NNK-N-oxide) and 4-oxo-4-(3-pyridyl)-1-butanol (keto alcohol) were quantitated by HPLC. The results showed that, in addition to alpha-hydroxylations, cytochrome P450IIB1 also catalyzed the formation of NNK-N-oxide efficiently, and to a certain extent, the conversion of NNK primary hydroxylation metabolites (keto aldehyde and keto alcohol) to secondary metabolites (keto acid and hydroxy acid). Cytochrome b5 at a ratio of 1:1 or 2:1 to P450IIB1 had no significant effect on the metabolic activities and profiles of NNK. The apparent Km values for the formation of keto aldehyde, NNK-N-oxide and keto alcohol were respectively 191.2, 131.4 and 318.0 microM with corresponding apparent Vmax values of 89.7, 295.5 and 333.3 pmol/min/nmol P450, indicating that hydroxylation at the alpha-methyl position is preferred over the alpha-methylene position. Measurement of formaldehyde, a product derived from the alpha-methyl hydroxylation, was developed as a convenient method to study NNK metabolism. Thiourea activated cytochrome P450IIB1-catalyzed NNK metabolism significantly. Phenethyl isothiocyanate, an inhibitor of NNK-induced lung carcinogenesis, inhibited P450IIB1-catalyzed NNK demethylation in a concentration-dependent manner. This work demonstrates that purified P450IIB1 can catalyze the conversion of NNK to most of its oxidative metabolites.

Metabolic activation of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone as measured by DNA alkylation in vitro and its inhibition by isothiocyanates

The bioactivation of the tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), by microsomes from target organs was studied with an in vitro microsome-mediated DNA alkylation system. Mouse lung, rat lung, and rat nasal microsomes catalyzed a time- and protein-dependent DNA methylation by [methyl-3H]NNK with activities of 4.11, 0.95, and 137.4 pmol/mg DNA/mg protein/h, respectively. The DNA methylation of NNK catalyzed by all three microsomal systems was inhibited by cytochrome P-450 inhibitors, such as carbon monoxide and metyrapone, but not by the cyclooxygenase inhibitor, aspirin, or by prolonged preincubation in the absence of NADPH. The possible involvement of specific P450 isozymes was assessed by specific inhibitory antibodies. An anti-P450IIB1&2 antibody significantly inhibited the DNA methylation by 45 and 32% in mouse lung and rat lung, respectively, whereas anti-P450IA1 and anti-P450IIE1 antibodies failed to show significant inhibition. All antibodies showed no inhibition in rat nasal microsomes. Glutathione inhibited the DNA methylation in a concentration-dependent manner in all three microsomal systems. Phenethyl isothiocyanate (PEITC), at doses of 0.25 and 1.00 mmol/kg body weight, was given intragastrically 2 h before sacrifice to mice and 24 h before sacrifice to rats, respectively; both mouse and rat lung microsomal activities were inhibited by about 40 and 90% by the low- and high-dose PEITC treatments, respectively. The rat nasal microsomes were only inhibited by the high-dose PEITC treatment by about 40%. PEITC, 4-phenylbutyl isothiocyanate, and 6-phenylhexyl isothiocyanate all inhibited the microsome-mediated DNA methylation of NNK in vitro, with 4-phenylbutyl isothiocyanate and 6-phenylhexyl isothiocyanate being more potent than PEITC and the mouse lung microsomes more sensitive than the rat lung and nasal microsomes. All three microsomal systems were shown to catalyze the in vitro DNA pyridyloxobutylation by [5-3H]NNK. On an equal protein basis, the rat nasal microsomes were much more active in catalyzing the DNA pyridyloxobutylation.

Effects of excess iodine in chick embryo thyroid follicles: initial inhibition and subsequent hypertrophy

The effects of excess iodine on the development of the thyroid gland of chick embryos was assessed following injections of potassium iodide prior to incubation. Iodide injection resulted in a significantly greater thyroid gland weight (goitre) on Day 18 of incubation and a delay in hatching. Histological studies of the thyroid gland on Day 12 of incubation revealed that iodide injection had inhibited thyroid follicle development. On Day 14, however, the thyroid glands of the iodide-treated embryos were indistinguishable from controls and on Day 18 the thyroid follicles of the iodide-injected embryos were clearly hypertrophied. In agreement with these light microscopical observations, electron microscopical examination showed conspicuous development of rough endoplasmic reticulum in the follicle cells of both iodide-treated 14 and 18 days old embryos and in those of the corresponding controls. Immunocytochemical studies of the pituitary of 18 days old embryos revealed a depletion of immunoreactive TSH suggesting that the iodide-induced hypertrophy of the thyroid was mediated by an activation of the thyrotropes. Iodide treatment was without effect on plasma levels of T3 and T4 for Day 18 embryos suggesting that the compensatory hypertrophy of the thyroid gland was sufficient to maintain circulating levels of thyroid hormones. The present results demonstrate that, in the embryonic chick thyroid, excess iodine produces effects which occur in two phases. The first phase consists of a transitory inhibition of the formation of follicles; it is followed by a second phase of compensatory hypertrophy resulting in goitre. The first phase probably results from a direct inhibitory effect of iodine on the developing thyroid whereas the second phase probably reflects a stimulation of the thyroid by TSH.

Studies on antipeptic ulcer agents: the quantitative structure-activity relationship analysis of heterocyclic aldehyde N4-substituted phenyl (thio) semicarbazones

Forty-five condensation products of furan-, pyrrole- and N-methyl pyrrole-alpha-carboaldehyde with N4-3- or N4-4-substituted phenyl semicarbazones and thiosemicarbazones were designed to optimize the antiulcer activity of a previously derived lead structure, formula II. Quantitative structure-activity relationships revealed that among the series of semicarbazones, increasing hydrophobicity and the introduction of electron-donating groups into the phenyl ring raise the antiulcer activity. Generally, semicarbazones are more active than the corresponding thiosemicarbazones. The wide gulf between the activity and toxicity of two derivatives (Compounds III and IV) necessitates further investigation of their pharmacological effects.

Polymorphisms in the human X-linked pyruvate dehydrogenase E1 alpha gene

Pyruvate dehydrogenase E1 alpha deficiency is an X-chromosome-linked disorder, often with fatal consequences. We have searched for genetically useful polymorphisms in or near this gene. No restriction fragment length polymorphisms were detected using a battery of 36 different restriction enzymes and probing with a full-length cDNA fragment, or two single-copy genomic fragments located within intron 8, and 15 kb 3' of the coding region, respectively. The chemical cleavage method was then applied to the detection of base changes in or near the gene. One polymorphism was found in exon 8 of the coding region. However, no base changes were detected in intron 3 or in the part of intron 8 covered by fragment gB2. Three blocks of microsatellite DNA containing variable numbers of CA-repeats were isolated from the 5' end of the gene and characterized. Length polymorphisms in these microsatellite DNAs were analysed using the polymerase chain reaction. Although the three loci are tightly linked, the polymorphisms appear not to be in disequilibrium, making them useful markers in linkage studies of the pyruvate dehydrogenase E1 alpha gene. Of 31 females analysed 12(39%) were heterozygous for at least one length polymorphism of the three (CA)n alleles.

[Study of the mechanism of gastrodin and derivatives of gastrodigenin]

The tritiated alpha-isobutylhydroxybenzyl alcohol (3H-G018) was found to be able to bind benzodiazepine (BZ) receptor on the rat brain membrane. The 125I labeled G-018 also had the similar binding activity with this receptor. In the present investigation, we observed that gastrodigenin and its derivatives inhibited the 125I-G018 binding of BZ receptor competitively, but no inhibition was observed with gastrodin. The results suggested that Gastrodigenin was bound to BZ receptor, and otherwise, gastrodin would have no direct interaction with BZ receptor. Probably, it might metabolize into gastrodigenin in vivo, and then got through the blood brain barrier and bound to BZ receptor, which mediated its pharmacological effects on the central nervous system.

Delayed radiation encephalopathy after radiotherapy for nasopharyngeal cancer: a CT study of 45 cases

The CT features of 45 cases of delayed radiation encephalopathy (including radiation necrosis) following radiotherapy for nasopharyngeal carcinoma are reported. The brain lesions were uni- or bilateral and involved mainly the white matter and subsequently the gray matter of the lower portion of the brain included within the portals of irradiation and its vicinity. The lesions were edematous and hypodense on CT and showed postcontrast enhancement in 50% of the cases. Within the period of follow-up (1-5 years), the lesions showed remissions and exacerbations and in some cases stabilized. In addition, there was progressive cerebral atrophy, manifesting itself mainly as dilatation of the temporal horns, the neighboring cisterns, and sylvian fissures. In some cases that were followed for a long time, the cerebral lesions showed either foci of calcification or encephalomalacia and/or porencephaly.

Somatic embryogenesis and plant regeneration in Acanthopanax senticosus

Mature embryos of Acanthopanax senticosus explanted on Murashige and Skoog (MS) medium with 0.5 mg/1 2,4-D developed somatic embryos directly from swollen cotyledon and embryo axes within one to two months. When the somatic embryos were transferred to medium supplemented with 2,4-D (0.5 mg/1) or IAA (1-3 mg/1) or Zeatin (0.5 mg/1) and NAA (0.2 mg/1), additional somatic embryos developed. Most (93%) embryos germinated on the above medium without 2,4-D. Sixty-two percent of the plantlets survived in soil. Histological observations revealed that the somatic embryos originated from cell masses of epidermal and sub-epidermal origin. There was no cytological separation zone between the somatic embryos and cultured expiants. Consequently, embryos were difficult to separate from their expiant tissue.

TG repeat polymorphism at the D21S167 locus

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[Relation of cytochemistry changes in the peripheral blood ANAE in chronic glomerulonephritis and differentiation-syndromes]

The ANAE reaction of the peripheral blood from 24 patients of chronic glomerulonephritis (grouped according to the identification of TCM) and 30 normal individuals were observed by cytochemistry and microspectrophotometry. It was found that the percentages of positive lymphocytes of the deficiency of Kidney-Yin was 47.8 +/- 7.6%, among which the percentages of lymphocytes of spot granular pattern and scattered granular pattern were 42.4 +/- 6.3% and 5.4 +/- 2.2% respectively, the ANAE relative quality of monocytes of the deficiency of Kidney-Yin was 51.26 +/- 2.59. They were 39.7 +/- 7.4%, 31.2 +/- 5.8%, 8.5 +/- 2.7% and 41.84 +/- 2.66 respectively in the deficiency of Kidney-Yang. The results of normal group were 65.5 +/- 6.8%, 53.6 +/- 6.7%, 11.9 +/- 3.4% and 54.78 +/- 3.34 in their given order. The differences in three groups each other were marked significantly. The authors have found the difference between the patients of chronic glomerulonephritis and the normal individuals was significant statistically.